1. Field of the Invention
This invention relates to shock absorbers and especially to shock absorbers which can be adapted to provide variable damping factors depending on road surface conditions.
2. Discussion of Related Art
Conventional shock absorbers impose a typical compromise between ride quality and handling performance. Usually the high damping required for good handling is excessive for acceptable ride quality on most roads which produce significant vertical impacts. The compromise usually is to adjust the compression damping of the shock absorber to 25%-40% of the extension damping to prevent excessive forces being transmitted during impactive compression strokes. This compromise resolves some of the severity of rough road impacts but still presents problems with ride and handling.
Shock absorbers have been suggested which have a variable damping ratio controlled by a ride or road sensor. In response to the output of the sensor, a control circuit adjusts the damping of the shock absorber to provide a smooth ride. Such systems, however, require complicated and costly controls to function properly.